lock held by in-doubt distributed transaction

Hi folks,
One of our developers has just reported this error after a simple select:

select COUNT(*) FROM tracking.tracked_lacosa_request

*

ERROR at line 1:
ORA-01591: lock held by in-doubt distributed transaction 4.18.4935

So I looked for the in doubt transaction as follows:

select * from dba_2pc_neighbors;

and

select * from dba_2pc_pending;

but both returned no rows.

I tried the same query and also get the same error. I bounced the
database (immediate) and still get the error and all the time with the
same transaction id 4.18.4935. I got the developers to bounce their jboss
but no joy.